Inlet manifold for internal-combustion motors



Oct. 11, 1927. 5,347

R. M. PIERSON INLET MANIFOLD FOR INTERNAL COMBUSTION MOTORS Filed Sept 1.4, 1921 fla s. T

Patented Oct. 11, 1927.

* UNITED STATES rarest? PATENT OFFICE.

ROBERT M. PIERSON, OF AKRON, OHIO, ASSIGNOR TO PACKARD MOTOR CAR COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

INLET MANIFOLD FOB INTEB-NAL-GOMBUSTIOK MOTORS.

Application filed September 14, 1921.

This invention relates to internal combustion engines and more particularly to fuel supply means therefor.

Inlet pipes for internal combustion engines generally operate to conduct a combustible mixture of air and semivolatile liquid fuel such as gasoline, drawn by suc tion of the pistons from a carburetor. These pipes, known in the art as manifold pipes, necessarily have one or more bends. It is known that when an engine is idling and the throttle is nearly closed, the fuel mixture in the intake pipes is traveling at or near its lowest rate of speed, and the unvaporized portion of the gasoline or similar fuel tends to separate and collect on the walls of the manifold, particularly at and in the immediate vicinity of the lower inner sides of the bends or turns in the manifold, where eddies occur, this phenomenon being commonly known as loading. This loading often causes the motor to fire irregularly and to ultimately stop. Itis also the cause of choking and of poor acceleration when the throttle is suddenly opened, because the excess fuel tends to unduly enrich the mixture. Then the mixture is traveling at high velocity, some deposition of fuel in the form of a film on the manifold walls takes place. No simple remedy for these conditions that will adequately prevent loading has heretofore been proposed. Loading can be overcome by a sufiicient degree of pre-heating but at the expense of unduly reducing the volumetric etficiency under open throttle conditions.

An object of the invention is to supply a proper mixture of fuel to the cylinders of an internal combustion engine at all speeds.

Another object is to reduce the deposition of'liquid fuel upon the walls of the intake pipes of a motor vehicle.

A feature of theinvention is an intake manifold for internal combustion engines which includes means for producing relatively small jets of air or other fluid at the place or places where the fuel tends to collect or to form a film. Preferably these jets are employed in combination with manifold heating means which may be of a special character constituting another feature of the-invention and deslgned advantageously to localize the heat and so to control it as to avoid overheating,

Serial No. 500,672.

is a section on the line 2-2 of in place by the usual T-olamps 32. 18 is an ordinary form of spray carbureter having a float-bowl 19, a mixing chamber 20 and a throttle-valve 21 at the outlet of said chamber, the carbureter in this instance being of the horizontalor side -outlet type bolted to the inlet manifold with a flanged connection at 22, and the trunk 15 of the manifold having a bend or turn at its lower end to conduct the mixture into the upright portion of said trunk.

The anterior portion with reference to the direction of flow oft-he combustible mixture, in this case the lower bend, of the inletmanifold being the coolest portion where the most intense evaporation is taking place, and where the unvaporized fuel in the mixture tends to be thrown out against the lower wall of the bend by gravity and inertia or centrifugal action, I furnish a substantially uncooled supply of exhaust heat to this portion by providing it with a local jacket or heating chamber 23 having body walls cast integrally with the manifold trunk 15, and a removable cover 24 held in place by a pair of screws 25, 25, this chamber being directly connected with the exhaust manifold 11 through a branch exhaust pipe 26 consisting of a piece of flexible metal tubing ter, and the products of combustion. atteri gii ingup a considerable portion of. their heat to the Walls .of the chamber andie's per.

cially to the lower ii allot the bend in the ti'on 1n the carburetor "itself but ben beiii'g usefulmainlyii'l pfoinoting va 1 intake passage, against which; they directly impinge on entering, find an outlet into the combustible mixture in said passage through a small fixed orifice 30. Preferably this orifice is located-"at ornear the lower side of the bend, so-that its gaseous jet will tend to pick up any liquid fu'e l which is tollowing t he Wall of the passage in that locality, and itis also positioned ator near the lowest point of the heating chamber 23 so as to drain said chamber of the Waterof condensation troiri the exhaust gases which would otherwise tend to eo'llect. 31 isabat fle' extending partay across the chamber 28 for deflecting. the gases therein and increasmg the heat transm tting surface.

An arrangement for supplying a moderate degree of heat 'tothe upper or posterior portion of the inlet manifold l l is provided by casting on the upper front part or its hori Zontal section a ebstructur'e or shield comprising a middle member 33 and two end members 34: partly. separated by a pair of recesses 35a) accommodate the adjacentlends of the two iniddleT-clan ps 32, the members 34 beingsuitably perforated for the passage of the stems of said elanip s. This Web structure islocated in the outer plane of the exliaust manifold as Will be eyident'in The upper edge of this web structure is brought close to the eri ha'ust manifold; so that a substantial closure ofthe outer side of the space included. between theinletand i i exhaust manifold s effected Cooling currents of air are thereby substantially eat eluded from said space arid the transmission of heat from the. exhaustmanifold to the Webbed inlet manifold, both "convection in the enclosed air space and byradiation, is promoted. forming this Web structure integrally ith the inlet manifold, its conductive efiiciency is increased compared With a separate shield and the ihanitold and shield can be manufactured and handled as l fii r m. 1'; i y y O er h ats l dii i i 1 5 0*? f?? i addition to those described lie resorted. to. The air supply to thefcarbi reter naiy, for example, beheatedby the e'z ilihu's't pipe te e (n eh nhflli lty h te -teams av diiieldeiq s tie b l a i feel in e k r 'sas a es a a "t eau gwliich iin'diily loi vers the volutr ee e y I In the loi'ier' Walls of lh orii loiitial branches 16, 16 of the inlet irianifoldfat or immediately beyond and on the inner sides ofh the bends or turns, from the trunl: 15 into these ,;liranches, I "p iovi' de a: pair of smalhfixecl at permanently-open air-bleeder orifices 3o, 36, Whosefunction is to supply jets or cold 'ai'r' for up or atoinizing the poolsof liquidfuel Whichtend to collect at .these 'points duringidling or slow running of the motor, a tendency due to or pro lnoted byth'e occurrence of eddies at these bends. These film-breaking orifices have been'fou'n'd to be very effective for the purpose, especially as the velocity of the jets is greatest When most needed, namely when the throttle is in a nearly closed position giving a strong-suction While the mixture is traveling-at a slow speed through the manitold, While these jet orifices may be used 1n the sameor an analogou'sposition 1n any vtype of inlet manifold for li'quid-fueland a r mixtures, it is preferred to employ them,"

as shon' min' combination With means such as the jet-orifice 30 for injecting a supply of cooled productsof combustion into the mixture on the posterior side of the throttle,

since theiiddedair-supply through the orifices 6 is compensated by the dilution of the mixture through theorifice 30, and thus the motor may be held to low minimum power Without irregular firing; bysuitable' adjustment of the throttle valve. The orifices 36 being of relatively minute size, do

For a Ford motor the hole 30 may be made by a No. U. Sfsta ndard Wire-gauge drill and the holes 36 No. 65 "drill, but these sizes 'iii'ay be considerably Varied. I V I do notlimit myself as to the eiiactch'aracter and arrangement of the several-de- -.-i ,4 :1, scribed expedlents nor to the use of all of these features 'in combination.

1. The coinbinatioh of internal-combustion motor, liquid-fuel carburte'r, inlet -'-ptfs sa ge h mg a t'urh, a filmmetatarsa -breeder; orifice at tir less: side of said tiirh, said orifice 'bin'g 'arih'anently open *toftlie as osph're.

take arad sighs-sweetie, summ rise-T bustion motors having an uptake portion, lateral branches leading from its upper end, and small air-jet orifices on the lower posterior sides of the turns from said uptake portion into the branches, said orifices being permanently open to the atmosphere.

4. The combination of an internal-combustion motor, a liquid-fuel carbureter, an intake pipe connecting said carbureter with the motor, a film-breaking air-jet inlet to said pipe, and means for admitting to said pipe a compensating jet of products of combustion.

5. The combination of an internal-combustion motor, a liquid-fuel carbureter, an intake manifold having an uptake portion connected with the carbureter and lateral branches connected with the motor, air-jet orifices on the under sides of the turns from said uptake portion into the branches, and means for admitting a supply of products of combustion into the combustible mixture in said uptake portion.

6. The combination of an internal-combustion motor having an exhaust passage, a liquid-fuel carbureter having a horizontal outlet. an inlet pipe provided with a heating chamber and having an uptake formed with a bend at its lower end connecting with the carbureter, a branch connection from the exhaust passage for sup-plying hot gases to said chamber, and a jet outlet from said chamber into the inlet pipe on the lower side of said bend.

7. An explosion-motUr intake pipe having an uptake portion formed with a. bend at its lower end, and a heating jacket localized substantially at said bend and having an inlet for hot exhaust gases at its upper end and a highly-restricted outlet leading from its lower end into said intake pipe. 7

8. The combination of an internal-combustion motor having an exhaust pipe, and a separate inlet pipe integrally formed with a shield covering the space between the two pipes and located in the outer plane of the exhaust pipe.

9. The combination of an internal-combustion motor having an exhaust manifold provided with downwardly-extending inlet branches, a separate inlet manifold located below said exhaust manifold and integrally formed with sections of a shield structure located in the plane of and between said branches and covering the space between the two manifolds, and clamps common to the two manifolds for holding them in place.

10. An inlet manifold for internal-combustion motors having an uptake trunk portion, a laterally-branched upper portion thereon, and an upwardly-projecting shield structure integrally formed on said upper portion and comprising a middle section and two end sections separated by recesses for accommodating the branches and clamps of an exhaust manifold. T

11. The combination of an internal-com bustion motor having an exhaust passage, a spray carbureter, an inlet manifold, means for imparting exhaust heat to the posterior portion of said inlet manifold, and permanently-open gaseous-jet means to assist in holding the fuel in suspension in said manifold adjacent to the heating means.

12. The combination of an internal-combustion motor, a spray carbureter, an inletmanifold having an uptake portion provided with a lower bend and posterior lateral branches'at its upper end, means for separately heating said bend and the posterior portion of said manifold, and jet inlets through the walls of said manifold at the lower side of said bend and at the lower posterior sides of the turns from the uptake portion into said branches.

13. In an internal combustion engine fuel supply system, a carburetor, an intake pipe having an uptake portion including a lower bend, connecting said carburetor to said engine, an exhaust manifold, and a conduit connecting the lower portion of said bendv to said exhaust manifold, said conduit including a small duct adapted to supply a spray of gas to the interior of said intake pipe for vaporizing excess fuel.

In testimony whereof I have signed my name to this specification.

ROBERT M. PIERSON. 

